Improvement in steam-generators



JOHN SHEFFIELD, OF BUFFALO, NEW YORK.

Letters Patent No. 39,249, dated April 2o, 1869. l

IMPROVEMENT IN STEAM-GENERATORS.

The Schedule referred to in these Letters Patent and making part of tho lama.

To all whom it may concern:

Be it known that I, JOHN SHEFFIELD, of the city of Buffalo, in the county of Erie, and State of New York, have invented an Improved Hot-Blast Apparatus for Steam-Boilers; and I do hereby declare that the following is al full, clear, and exact description thereof, reference being had to the accompanying drawings, making part of this specification.

The nature of my invention consists in the arrangement, within the smoke-pipe or chimney, of a steamboiler, of an internal induction-air flue, connecting with the furnace of the boiler, and supplying the same with air for combustion, whereby a large portion of the waste heat, in the products of combustion, escaping through the chimney, is absorbed by said air-current, and returned to the furnace, and utilized.

In the drawings- Figure I is a longitudinal section of a steam-boiler, with its furnace and chimney, showing the application of my improvement thereto, and

Figure II is a cross-sectional elevation of same.

Like letters refer to like parts in each of the figures.

A represents a steam-boiler,.of any approved construction. Y

B represents the furnace thereof, which is also of any approved construction.

C represents the smoke-pipe, or chimney, arranged and combined with the boiler in any suitable manner.

D represents the induction-air pipe, arranged within the chimney, and extending longitudinally through the same, so that the products of combustion, as they escape into and pass through the chimney, will be carried along in contact therewith.

D represents a horizontal extension of the air-pipe to the furnace B, into which it opens, below the gratebars, the furnace having a tight ash-pit, so that the air discharged therein from pipe D', will be obliged to pass into and through the fire.

E represents a centrifugal fan-blower, interposed between the parts D and D', of the air-pipe, at their junction, or otherwise arranged so that by its operation it will create, by suction and blast, an inward current through D and D', into the furnace, and an outward current from thence through the boiler-ues and chimney.

F represents a bell-mouthed cross-pipe, at the top of induction-pipe D, supported on a vertical axis, on which it is free to turn, and provided with a vane, F. by which its mouth is kept toward the wind, so that a supply of fresh air, without mixture with the escaping smoke is thereby insured.

It is well known that even in boilers of the most approved construction, a large amount of the heat arising from the combustion of the fuel, escapes into the chimney, even when the combustion is the most perfect.

By the arrangement ofthe air-flue in the chimney, this waste heat will, to a very great extent, be absorbed by the ingoing current of air, and carried back to the furnace, and utilized, in promoting the combustion of the fuel.

The fan E becomes a necessary adjunct from the fact that as the ingoing current absorbs the heat from the outgoing current, it weakens the draught, so that the same requires to be kept up by artificial means.

Having thus described Vmy invention,

lVhat I claim, and desire to secure by Letters Patent, is-

The arrangement of the induction-air pipe D, within the chimney O, and with its extension D', communicating with the furnace B, as herein described.

JOHN SHEEFIELD.

Witnesses:

W. H. FoRBUsH, VICTOR H. BECKER. 

